analog delay repair advice please :)

[doug deeper]

so i just bought an electra analog delay (a table top unit from the 70's i think)
and its sounds fine for about 5 seconds when first turned on then the repeats get REALLY fuzzy and the longer delay times just whistle a bit.
beacuse this takes a few seconds to happen i imagine its caps, but do you think it would be power caps (the unit has a built in transformer)
or do you think its the bbd?
or something else!

thanks in advance!

[Meanderthal]

 Naa, if the bbd was fried it wouldn't work at all. I'd bet on the power supply.

[Mark Hammer]

My first inclination is the cap that might be smoothing the Vref.  Many budget delays will use a single fixed Vref to provide the bias voltage as well as the Vref for the rest of the audio path.  If Vref/Vbias drifts due to cap problems then sonic quality will drift as well, similar to what you'd get by tweaking a bias trimpot.

So, not quite power supply but sort of.

[Ronsonic]

Three letters and a word "ESR Meter."

The Dick Smith kit is excellent and has saved me a world of diagnostic time.

Not having one, just start replacing electrolytic caps in the order of funkiest looking (bulges, leaks, etc.) highest voltage, whatever looks important.

Ron

[doug deeper]

cool thanks!
i was planning on just replacing caps, but then i read somewhere that bad bbds can cause this nasty fuzziness.
this thing sounds great for those couple seconds so im pretty psyched to get in back into shape!

[MartyMart]

Good luck with that Doug , I have an Ibanez AD150 that "howl's" and feeds back like crazy !
Need to get "de-buggin" also !

MM.